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THE MINISTRY of EDUCATION and SCIENCE of RUSSIA FEDERATION SAMARA STATE AEROSPACE UNIVERSITY

System Analysis of Space Missions

Electronic Laboratory Course

SAMARA
2011


629.78 22.62 Compilers: Belokonov Vitaliy Mikhailovitch, Belokonov Igor Vitalyevitch

Editorial processing: I. V. Belokonov Computer imposition: I.V. Belokonov System Analysis of Space Missions = [Electronic resource]: Electronic Laboratory Course / The Ministry o f Education and Science of Russia Federation, Samara State Aerospace University; compilers V. M. Belokonov, I. V. Belokonov. - Electronic text and graphic data (1,8 Mb). - Samara, 2011. - 1 CD-ROM. The present laboratory practice on discipline «System Analysis of Space Missions» urged to give practical skills in carrying out of the complex analysis of almost any typical missions in a circumt erraneous space. Proble ms in a practical work represent a complex of the interconnected problems under the analysis of feasibility of space mission, beginning from a stage of space vehicle launching to a stage of de-orbiting and landing. Practical work main objective is fastening of theoretical knowledge on discipline and mastering by pupils of the basic engineering techniques used at the syste m analysis of space missions. The practical work also promotes quantitative estimations of design-ballistic characteristics for typical operating conditions of space vehicles, and can be used at final master thesis works. Interuniversity Space Research Department, Master Program Educational Content "Space Information Systems and Nanosatellites. Navigation and Remote Sensing" for education direction 010900.68 «Applied Mathematics and Physics»

© Samara State Aerospace University, 2011


THE CONTENT INTRODUCTION The concept of a laboratory practice The task and initial data for practical work performance under the analysis of space mission Sequence of performance of the analysis of space mission The analysis of supernumerary variants of realization of space mission The description and the instruction on application o f START program complex for the launching of space vehicle into an intermediate orbit The introduction for START program complex The description of the interface of program complex START The instruction on application of STK program for the system analysis of space mission Initial skills of work by STK The analysis of orbital missions by STK P. 3 6 6 9 15 17

1 1.1 1.2 1.3 2

2.1 2.2 3 3.1 3.2

17 18 28 28 54


INTRODUCTION

The present laboratory practice on discipline «System Analysis of Space Missions» urged to give practical skills in carrying out of the complex analysis o f almost any typical missions in a circumterraneous space. Proble ms in a practical work represent a complex of the interconnected problems under the analysis of feasibility of space mission, beginning from a stage of space vehicle launching to a stage of de-orbiting and landing. Practical work main objective is fastening of theoretical knowledge o n discipline and mastering by pupils of the basic engineering techniques used at the system analysis of space missions. The practical work also pro motes quantitative estimations of design-ballistic characteristics for typical operating conditions of space vehicles, and can be used at final master thesis works. The laboratory practice supports almost all questions reflected in the lecture courses on given discipline. The laboratory practice consists of three parts and two appendices. In the first part the laboratory practice concept is described, the sequence of solved problems, structure of the initial data describing space mission is in details stated. The initial data at practical work performance are design c haracteristics of the carrier rocket of space appointment, the requirement to the space vehicle, defining its special-purpose designation and technical characteristics (including parameters of a working orbit), the basic design characteristics of the space vehicle and its onboard systems. In the second part the description, and also the instruction on application o f progra m complex START for the analysis of use of the chosen type of the carrier rocket of space appointment (CRSA) for delivery of the set useful loading (space vehicle) to a launching orbit is resulted. Program complex START is written in language of high level JAVA. This language allows to create the convenient


interface and effectively to organize educational process not only in internal, but also in the remote form. In Appendix1 settlement techniques and models for the analysis of feasibility o f deducing of the set useful loading chosen CRSA are short stated and the sequence of performance of various types of tasks are described. In the third part the instruction on application of a specialized license package of applied progra ms STK (Satellite Tool Kit) for the system analysis of space missio n is resulted. This package is used for the analysis of following stages: - The analysis of the ballis tic scheme of flight in a regular mode of functioning of the space vehicle, - Estimations needed stock of fuel onboard the space vehicle, - The analysis of the ballistic scheme of flight in emergency operation. At the analysis of orbital stages following problems are solved: - A substantiation of a choice of type of a working orbit, - An estimation of an orbit evolution from action of Earth atmosphere (including calculation of the space vehicle existence time and etc.) and fro m Earth non-centra l gravitational field, - Calculation of space vehicle transfer maneuvers fro m a initial orbit into a working orbit, - Calculation of working orbit maintenance maneuvers (maintenance of the set height of flight, move ment maintenance in the set range of heights, a correcting of elements of an orbit) on an interval of time of active existence in an orbit, - Calculation of a line of flight and the auxiliary ballistic information (conditions of mutual visibility of the space vehicle and land point, operability of areas of a terrestrial surface from a board of the space vehicle, conditions of light exposure o f the space vehicle), - Calculation of a brake impulse, a point of its appendix and the characteristic of a n extra-atmospheric site of the flight previous descent of the space vehicle in atmosphere,


- A choice of demanded conditions of an input and movement calculation in atmosphere. In the Appendix 2 the basic theoretical positions are short stated and the sequence of performance of the various typical tasks connected with the analysis of separate stages of space mission is described. The especial attention is given skills of check of possibilities of flight control, planning of sessions of the tele meter information reception, an estimation of visibility conditions and light exposure of various areas of a terrestrial surface. In laboratory practice the materials prepared earlier by professor I.Timbai and post-graduate student V.Travin were used.


1. The concept of a laboratory practice

1.1. The task and initial data for laboratory practice k performance under the analysis of space mission 1.1.1 Special-purpose designations and key parameters of space mission Space vehicle special-purpose designation (the companion meteorological, researches of natural resources of the Earth, communication navigating etc.) ______________________________________________________________ Full mass of the space vehicle after separation fro m the carrier rocket in kg

_______________________________________________________________ Mass of payload in kg _______________________________________ in in __________________________ ________________________

The middle square of space vehicle The middle square of recovery capsule

Ballistic coefficient of the space vehicle

___________________________ __________

The maximum of aerodyna mic quality for recovery capsule Specific impulse for maneuvering engines

in km/s ___________________ ___________________

The angle of the visibility for onboard equipment The operating time of onboard equipment 1.1.2 Parameters of the realized orbit Task variant through orbit ele ments : Perigee height Apogee height Orbit inclination

in days________ ___________

in km _________________________________________ in km _________________________________________ _____________________________________________ ________________________________________ _______________________

Argument of a perigee

Longitude of the ascending node of an orbit


The angle of true ano maly in a orbiting point

(during the initial mo ment

of time) _______________________________________________________ Task variant through characteristics of the end of an active step of launching: Co-ordinates of a orbiting point in the initial orbiting time in starting coordinates system in ___________________________________________________ in ___________________________________________________ in ___________________________________________________ Projections of a vector of speed in starting coordinates system ___________________________ ___________________________ ___________________________ 1.1.3 Parameters of a final movement Parameters of a final orbit: Apogee height Perigee height Orbit inclination in km _________________________________________ in km _________________________________________ _____________________________________________ _______________________________________ in ________ in ________ in ________ orbit and _______________ km/s _______________ km/s _______________ additional requirements to km km km

km/s

Argument of a perigee

1.1.4 Additional requirements for frequency of carrying out of trajectory corrections For a circular orbit: Ad missible change of a longitude of the ascending knot of an orbit __________________________________________________________ Ad missible falling of height of flight For an elliptic orbit: In km ___________________


Ad missible change of a longitude of the ascending knot of an orbit in deg._____________________________________________________ Ad missible falling of perigee height in km ___________________ __________________

Ad missible change of argument of a perigee

1.1.5 Additional restrictions on orbital movement: Time period of stay in an initial orbit in days

___________________________________________________________ The maximum time of transition fro m a initial orbit into a final orbit in hours ________________________________________________ 1.1.6 Data for calculation of the auxiliary ballistic information Geographical width of land point Geographical longitude of land point ____________________________ _________________________

The minimum corner of an eminence of the space vehicle for its visibilities from land point _____________________________________ ______________________________ ___________ _______

Corner of declination of the Sun

Geographical width of start point for the carrier rocket Geographical longitude of start point for the carrier rocket

1.1.7 Data for calculation of maneuver of rapprochement with an orbiting station Initial angular distance between the space vehicle in an initial orbit and an space station in a working orbit _________________________________

Projections of a position vector of the space vehicle concerning an orbiting station after finishing of distant rapprochement (a miss by position) in m, in m, in m. Projections of a speed vector of the space vehicle concerning an space station after finishing of distant rapprochement (a miss on speed)


in km/s, in km/s, in km/s. 1.1.8 Parameters of a prerelease orbit and restriction on controllable characteristics of movement in atmosphere Inclination Flight height ____________________________________________ in km ____________________________________ ______________________ ___________________ _________

Geographical width of a point of descent Geographical longitude of a point of descent

The maximum ad missible value of an thrust-to-weight

The maximum ad missible value of a specific thermal stream in a critical point of the recovery capsule In ____________________________

The maximum ad missible temperature in a critical point of the recovery capsule a In °C. _______________________________________________

1.2 Sequence performance of the space mission analysis

1.2.1 Preparation of the initial data Before the beginning of performance of the space mission analysis it is required to fa miliarize with the initial data attentively. If para meters of a working orbit are not completely set, for exa mple, the orbit inclination, it is necessary to choose them independently on the base of a purpose designation of the space vehicle using mentioned below recommendations. The intermediate orbit of launching can be set by a set of elements or characteristics of the end of an active flight site in starting coordinate systems. On occasion it is required most to be calculated.


If the second form of the task of the initial data it is necessary to settle a n invoice by the resulted technique movement entry conditions in absolute geocentric coordinate system is accepted and to find elements of an launching orbit.

1.2.2 Analysis of the ballistic scheme of flight in a regular mode of functioning of the space vehicle

Calculation of movement of the space vehicle on the set interval in a launching orbit 1) the evolution of launching orbit, caused non-central gravity attractio n fields ( ) on time interval

2) the evolution of an orbit caused by influence of at mosphere ( ) on time interval .

3) the correction maneuver on maintenance of an launching orbit (for circular and near circular orbits - maintenance of flight height) and full expenses of characteristic speed are defined .

4) the flight trace of the space vehicle and the standard ballistic information (a zone of mutual visibility and light exposure of the space vehicle) ; - on an interval with use of progra m STK, thus coordinates of land

point get out of the initial data; - on an interval of two turns of flight - manually, thus as launching point gets out and geometrical characteristics of the review of a terrestrial surface are in addition calculated. 1.2.3 Analysis of maneuver of transition from a launching orbit into a working orbit (without phasing) Transition maneuver is determined in a class of two-pulse and threepulse energetically optimum maneuvers. In a case three-impulse maneuver the


apogee of a transitive elliptic orbit is limited fro m above from a condition not excess of time of transition of the set size .

In case the working orbit is elliptic, transition is carried out or in apogee, or in perigee. Thus settlement formulas of definition of impulses are deduce d independently with use of integrals of energy and the areas. Full expenses of characteristic speed and time of flight for each variant of transition are calculated.

1.2.4 Analysis of maneuver of rapprochement with an space station In the beginning maneuver of distant rapprochement (transition from a deducing orbit into a working orbit with phasing) is considered. The given calculation is carried out only for a transition case between circular orbits. If two-impulse flight the demanded corner of phasing is defined it is chosen as optimum. At the task of initial angular distance between the maneuvering space vehicle in an launching orbit and an orbiting station in a working orbit the waiting time to an establishment needed phasing corner on also is calculated. If it is chosen as optimum three-pulse be-elliptical flight the apogee of a transitive elliptic orbit from a condition phasing for the set initial corner of a mis match between space vehicles is defined needed velocity. Assuming that as a result of maneuver of distant rapprochement the space vehicle passes in a small vicinity of an orbiting station, finishing maneuver of a stage of rapproche ment pays off. It is considered that duration of rapprochement does not exceed a cycle time on an orbit. There is an optimum duration and parameters of maneuver fro m a condition of a minimalist of size of needed characteristic speed.


1.2.5 Analysis of correcting maneuvers for maintenance of a working orbit For a case of a circular orbit of deducing maneuver of maintenance of movement of the space vehicle in the set range of heights and longitudes o f the ascending node of an orbit in the set range of values pays off. For a case of an elliptic orbit of deducing correction maneuvers (in the assumption of their incoherence) separately for maintenance of height of a perigee, argument of a perigee, a longitude in the set interval of values according to the requirements formulated in the initial data. Frequency of carrying out of correction by calculation of evolution of an orbit is thus estimated, the quantity of maneuvers of correction and demanded expenses o f characteristic velocity on an interval of time of active existence Results of calculations are represented in the form of tab. 1 for a circular orbit and in the form of tab. 2 for an elliptic orbit. Table 1 Correction o f an element of an orbit Conditional frequency of correction per 1/days Expenses of characteristic speed for 1 correction in km/s Quantity of corrections on an interval Expenses of characteristic speed for an interval in km/s

H Full expenses of characteristic speed in km/s Correction o f an element of an orbit Frequency of correction per 1/days Expenses of characteristic speed for 1 correction in km/s Quantity of corrections on an interval Table 2 Expenses of characteristic speed for an interval In km/s

H Full expenses of characteristic speed in km/s


1.2.6 Analysis of maneuvers at a stage of delivery of payload to the Earth Maneuvering at a stage of delivery of the information to the Eart h includes maneuver of transition of the space vehicle fro m a working orbit into a initial orbit and maneuver of braking for input realization in dense beds of atmosphere with the set conditions of an input. The maximum angle of entry on the module Approximately it is

possible to estimate for the set type of the capsule, substituting instead o f , , Their maximum permissible values. Thus speed of an

input is necessary equal ~8 km/s. The initial orbit is considered circular. If height of a initial orbit it

is set, parameters of transition maneuver. Then maneuver of a descent fro m a initial orbit pays off. If the height of a initial orbit is not set, it gets out of a condition o f minimization of full expenses of characteristic velocity on maneuver o f transition to a initial orbit and on maneuver of a descent from a initial orbit. The optimum height of a launching orbit can be in any image, for example, searching in the chosen range of heights.

1.2.7 Analysis of a de-orbiting stage to the Earth For chosen of a brake impulse of velocity and a corner of its

orientation and speed and an angle of entry in de nse at mosphere, angular range and flight time on an extra-atmospheric site are defined. Further on the set conditions of an input in atmosphere the decrease trajectory, considering that movement is carried out in a plane of a initial orbit at the maximum aerodyna mic quality. Performance of all restrictions on controllable characteristics o f movement is thus checked, and also rough co-ordinates of a point o f achievement by the landing of an Earth surface (without a movement site on a parachute). In case restrictions on a descent trajectory are not carried out; it is necessary to offer the measures providing their performance.


1.2.8 Calculation of full expenses of fuel on realization of considered space mission On the basis of results of calculation of characteristic velocity on all kinds of maneuvering received in the previous sections, tab.2 . The found full expenses of fuel of flight are compared to a fuel stock . If , then the considered ballistic scheme of flight is realizable on realization of the ballistic scheme available onboard the space vehicle:

also a fuel part it would be possible to translate in useful loading or to increase time of active existence of the space vehicle. In this case it is necessary estimate on how many days active existence of the space vehicle can to be prolonged.


Table 3 Expenses of characteristic velocity in km/s On maneuver of maintenance of an orbit of deducing On maneuver of transition fro m 2 a deducing orbit into a working orbit 3 4 On rapprochement maneuver On maneuver of maintenance of a working orbit On maneuver of transition fro m 5 a working orbit into a pretrigger orbit 6 Pas braking maneuver at a descent fro m a prestarting orbit Fuel expenses in kg. Duration of engine works in sec.

1

Full expenses

If

that the given ballistic scheme is not realizable and it is

necessary to offer variants of performance target , for example, to estimate time of active existence of the space vehicle proceeding fro m available onboard fuel stocks, or to define weight of useful loading for which the accepted ballistic sche me of flight can be realized.

1.3 Analysis of supernumerary variants of realization of space mission In a practical work the pupil should estimate two possible emergencies. 1. After branch of the space vehicle fro m the carrier rocket it is not possible to establish communication with it (or correcting impellent installation) has failed and the space vehicle makes no directional passive move ment.


In this case it is necessary: - To count up time of existence of the space vehicle for the minimum, average and maximum indexes of solar activity, - To define height of a critical orbit, - To calculate and construct schedules of change of height of flight fro m time before achievement of critical height. After achieve ment of critical height which practically coincides conditional border of dense atmosphere, the space vehicle begins move ment on a flat trajectory in atmosphere where there should be its destruction. For the analysis of process of destruction it is necessary to know overloads and thermal streams at movement. (Space vehicle movement therefore pays off with not separated lowered part) in atmosphere till the falling mo ment to the Earth. Thus it is necessary that there is a ballistic descent (=0), and the angle of entry is accepted equal ~-0,1 . 2. At the final stage of flight after a descent of the capsule fro m an orbit the movement control syste m has failed. In this case the capsule rotatio n concerning a longitudinal axis and ballistic descent in atmosphere is carried out. Trajectory and controllable characteristics of movement (overloads and specific thermal streams) also calculated and move ment entry conditions (input conditions in atmosphere dense beds) get out on the basis o f recommendations. As a result of calculation of emergency operation requirements to a design of the space vehicle and its lowered part fro m the point of view of their self-liquidation should be formulated at a supernumerary situation (compulsory destruction or self-damage).


2. The description and the instruction on application of the START program complex for the analysis of a launching space vehicle into an intermediate orbit 2.1 Block diagram of a START program complex
acvrb.ssau.ru/dinpol/

Calculation of flight of a step in atmosphere dense beds

Optimum maximum of an angle of attack The maximum high-speed pressure Final flight conditions

The task of a final angle of slope of a trajector y

The task of parametres for the decision of a regional problem

The task of design parametres of a step

Calculation of an intermediate step

The task of a final angle of slope of a trajector y

The task of final height of an orbit

Final flight conditions

(Without a passive site) (With a passive site) The task of parametres for the decision of a regional The task of design parametres of a step The task of entry conditions of flight

Schedules of a trajectory, speed and angle of slope o f a trajectory from time

Calculation of a finishing step

The task of a final angle of slope of a trajector y

The task of final height of an orbit

Final flight conditions

The task of parametres for the decision of a regional The task of design parametres of a step The task of entry conditions of flight

Choice from a database

Viewing of a full trajector y of flight

Viewing of a full trajector y flight on the world map (Google maple)


2.2. The description of the interface of the START program complex The START program complex (personal computer) supposes placing on the Internet for convenience of its use by pupils. As a result of any pupil can have access to modules of calculation of a launching trajectory. Besides the persona l computer allows establishing traditionally in a co mputer class on one computer, connected in a local network with other computers. At home page loading, the window for calculation of an atmospheric step opens, the screen copy is resulted in drawing 1. The left column contains the menu of the user with which help it is possible to choose an interesting kind of calculation, or to use additional functions such, as viewing of a full trajectory of the rocket, a choice flowing and viewing of a projection of a trajectory of flight of the rocket on card Google Maple. To see a full trajectory of flight, it is necessary to walk consistently on all modules of calculation of missile stages. At calculation of atmospheric steps the final data is automatically transferred to the initial data for calculation of an intermediate step (if the three-stage rocket) or in the initial data o f a finishing step (for the two-level rocket). Trajectory calculation begins with button "Modeling" pressing.

Figure 1 Main window of a program complex


The interface illustrated on an example of the analysis of possibility of deducing of useful loading of the set weight three-stage Rocket "Soyuz" (fig. 2)

Figure 2 Input of design parameters of carrier rocket

By pressing the reference «First step» there will be a window of calculatio n of a trajectory of movement of a step in at mosphere dense beds. As input parameters for calculation of the progra m of management and a flight trajectory it is necessary to set the initial data: - Parameters of the decision of a regional problem; - Design para meters of a step; - A final angle of slope of a trajectory. The screen copy is shown in Figure 3:


Figure 3 Task of the initial data for calculation of an atmospheric stage

Results of calculation: - Parameters of rocket flight at the moment of start, - Parameters of rocket flight at the moment of the termination of a vertical site,


Parameters of rocket flight the at the moment of achieve ment of a maximu m of an angle of attack, - Parameters of rocket flight at the moment of the termination of a site of an aerodynamic turn, - Parameters of rocket flight at the moment of achieve ment of a maximum of a high-speed pressure, - Parameters of rocket flight at the mo ment of the termination of work of a step, - Schedules of a trajectory of an angle of attack and speed. The copy of the screen reflecting results of calculation is shown in figure 4.


Figure 4 - Results of modeling of movement for an atmospheric stage


As variant of the rocket has three stages we pass to calculation of an intermediate stage, the screen copy is shown in figure 5. For calculation it is necessary to set the following entrance data: - Parameters of the decision of a regional problem, - Design para meters of a stage, - Flight entry conditions. The end result of modeling of an atmospheric stage will automatically be transferred to entry conditions of flight for an intermediate stage.

Figure 5 Entrance data for modeling of movement of an intermediate step

Copy of the screen of the received results it is shown in figure 6.


Figure 6 Result of modeling of movement of an intermediate step

In figure 7 the copy of the screen of the task of initial parameters for calculation of the third (finishing) stage is resulted.


Figure 7 Initial data for calculation of a finishing stage

In figure 8 the copy of the screen of results of modeling of flight of a finishing stagep is shown, and in figure 9 the full trajectory of flight is shown.


Figure 8 Results of modeling of flight of a finishing stage


Figure 9 Full trajectory of flight of the carrier rocket "Soyuz"

For reception of the information on used terms, techniques and models it is necessary to address to the Appendix of 1 given practical work.


3 Instruction on application of program complex STK for the space missions analysis

The present instruction allows users to get skills, skills for creation and manage ment of objects in personal co mputer STK. The pupil will get acquainted with structure of static and dynamic elements of a database of personal co mputer STK and will learn to keep and take objects fro m this base. After creation o f various objects in personal co mputer STK the pupil will learn to "recover" the project to receive the information, time-dependent in a window «Map». In additio n forms of reception of reports in static and dyna mic forms are described.

3.1 Initial skills of work by STK

The folder in which it is established STK, contains a subdirectory «Tutorial» in which the information received during independent work of the pupil at mastering of the personal co mputer re mains all. The first basic step is creation of the educational scenario. As the scenario is called the object of the highest level in STK it includes a card and comprises all other objects (companions, navigating equip ment etc.). This section of the program of training acquaints with process of creation and saturatio n by the scenario information. When for the first time it is started STK, in a separate window opens «Startup Wizard».


For creation of the new scenario it is required to press the button which is to the left of a field «Create a New Scenario» in «Startup Wizard» as a result the card window opens. For scenario renaming it is necessary to press an icon to the left o f a name, appropriated to the scenario by default, then addressed to Scenario# in the main window. After that it is typed «Tutorial40» in the allocated text and butto n Enter is pressed. The main window is updated for display of a new name.


Before carrying out any problems in STK it is necessary to establish para meters Tutorial40 which will influence all aspects of the scenario, after its creation. For performance of the problems put at the initial stage, it is expedient to use the parameters described further. There is a possibility to change para meters of the scenario in program work. First of all it is necessary to install parameters of applications STK as a whole. These parameters of the highest level influence any object in the appendix, irrespective of the open scenario. For installation of para meters of the appendix it is necessary to be convinced that the main window of the program actively. Click on the menu «Properties» and choose «Basic» in the e merged window. As a result there will be a window of base parameters. Important often to keep the project for prevention of loss of the information. It is possible to use an option of the Car of preservation.

For convenience it is necessary to be convinced that the auto preservation period is equal to 5 minutes, points «Auto save» and «Save Vehicle Ephemeris» are


included, and points «Binary Format» and «Save Accesses» are switched off. Press key for acceptance of changes and window closing «Basic Properties». It is important to establish parameters not only at appendix level, but also in the scenario. It is necessary to establish the units of measure used throughout all work and as to establish necessary parameters of a drawing for convenience of display and perception of objects and schedules on the screen. Units of measure get out by allocation by a mouse of scenario Tutorial40 in the main window and pressing Basic in the appeared window of properties. For test change time of the beginning of the scenario on 1 Nov 1997 00:00:00.00 and time of its termination on 1 Nov 1997 04:00:00.00. Then press on "Animation".


To make sure that the period is set correctly, check up field Start Time o n Animation 1 Nov 1997 00:00:00.00, then press on Units.


For convenience, establish all units of measure ments how it is shown in the table. To change values by default, allocate an element interesting you, then choose correct value in a window «Change Unit Value». To choose an element from the list, allocate with a mouse this element. To remove allocation, once again click it with a mouse.

Field Distance Unit (distance) Time Unit (time) Date Format (a date format) Angle Unit (corner) Mass Unit (weight) Power Unit (force) Frequency Unit (frequency) SmallDistanceUnit () LatitudeUnit (width) LongitudeUnit (longitude)

Setting Nautical Miles (n miles) Hours (hours) UTC Gregorian (the Gregorian calendar) Degrees (degrees) Kilogra ms (kgs) dBW GHertz () Meters (metres) Degrees (degrees) Degrees (degrees)

After the installation termination it is necessary to press the button APPRX. Drawing parameters operate information display to the screen and the possibilities accessible in window Map. To establish parameters of a drawing for own scenario, press the button of the panel of tools of a window of Mar. Properties of a card are responsible for information display: orbits, names of objects, lines and other information on the companion. In the table shown here, the option «Show Tool Bar» is included, and the option «Show Elevation Regions» is disconnected. For convenience, be convinced that options «Show Tool Bar», «Show Status Bar» and «Show Scroll Bars» are included, and the option «Show Elevation Regions option» is disconnected. After the termination, press on Details.


Further it is necessary to fill the scenario with various objects. It is expedient to begin with a choice and the task of placing of land stations, starting platforms and tracking stations. Press an icon «Facility icon» in the bottom part of the main window (when the cursor is directed at an icon in the bottom part of a window its value is highlighted). Change the object name, for example, on «Baikonur». At first it is necessary to allocate with double click of the mouse the old na me, and then to enter the new name in the allocated place. Pressing Enter carries out installation of a new name. As a result the Main window will be updated to display new object. In a window of the Card it will appear in a place with co-ordinates of 0 degrees of width and 0 degrees of a longitude. Further it is necessary to choose «Basic» from the menu «Properties» (or to press the right button of the mouse for menu occurrence in which it is possible to choose properties and tools for object). Installation of co-ordinates of object is carried out in the first Position windows Basic Properties. Coordinates set object position on a card.


For mastering check establish values on Position how it is shown more low, and be convinced that options Local Time Offset from GMT and Use Terrain Information are switched off.

Field Position type Latitude Longitude Altitude

Setting Geodetic 48.0 55.0 0.0

Further it is necessary to press Description. At any mo ment to receive the information on object it is necessary to use Description where it is possible to describe object independently.

Following stage of develop ment of possibilities of the personal computer is addition of new objects. For an example it is possible to add four more new objects, specified in the table. For this purpose it is necessary to execute the steps described above for addition of new objects, in details to describe objects unessential.


Name Perth

Latitude -31.0

Longitude 116.0

Altitude 0.0

Short Australian Tracking Station

Wallops

37.8602

-75.5095

-0.0127878

NASA Launch Site/Tracking Station

After definition of parameters of each object it is necessary to press the butto n APPRX. For addition of two more objects in the scenario we will use the Database. For this purpose in the main window it is necessary to allocate the created scenario, and then in menu Tools choose Facility Database.

It is necessary to include option Network and to choose, for example, NASA DSN, and further to press button Perform Search ...


After occurrence in a window of search results, find in the end of list Santiago and WhiteSands, then press APPRX. In window Facility Database press Cancel. In the main window allocate Baikonur, and then press and hold button Shift, in passing allocating all remained four objects, then press the right button of the mouse and choose Graphics in the appeared menu.

On Attributes change Marker Style so that it has displayed an object icon. Press APPRX.


When objects are added in the scenario from a database, for them the description is auto matically created. For description viewing, for example, object Santiago it is necessary to open menu Basic Properties for this object and to choose option Description.

Field Long Description contains except the information on a site and other data, concerning the allocated object. Creation of the purposes of supervision is an important stage of script writing. Let the supervision purpose is the glacier in the North America. It is necessary to press icon Target in the bottom part of the main window, then to designate purpose Iceberg and to press Enter.


Further it is necessary to press on Basic in menu Properties for the purpose of the task of co-ordinates of the purpose and its description. The first in window Basic Properties is called Position.

It is necessary to define a longitude, width and height above sea level for the new purpose. On Description the short description is entered. It is necessary to change Position Type on Geodetic.

Name Iceberg

Latitude 74.91

Longitude -74.50

Altitude 0.0

Short Only the tip

After the termination to press the button APPRX. That it is better to see object on the Card, it is necessary to open its graphic properties and to change Marker Style for an object icon. Creation of the scenario for mobile object is shown for the ship. In the beginning it is necessary to add the ship in scenario Tutorial40. It needs to press an icon of the ship and to change the name of new object on Cruise. Then it is necessary to press Enter to accept a new name. Further window Basic Properties for the below.


It is necessary to be convinced that start time on Route is established on 1 Nov 1997 0:00:00 AM and Propagator on Great Arc. Coordinates of move ment of the ship are entered . When input of a line comes to the end button Insert Point (the point through which will take place the ship is put) is pressed.

Latitude 44.1 51.0 52.1 60.2 68.2 72.5 74.9

Longitude -8.5 -26.6 -40.1 -55.0 -65.0 -70.1 -74.5

Altitude 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Rate 4.9 4.9 4.9 4.9 4.9 4.9 4.9

Turn radius 0.0 0.0 0.0 0.0 0.0 0.0 0. 0


Further definition of a site of the ship is carried out. It is for this purpose pressed Attitude in window Basic Properties and it is checked that in point Attitude Type it is established ECI velocity alignment with nadir constraint.

Further at scenario drawing up it is necessary to add companions and space vehicles. For example, are added ERS1, Shuttle, TDRS_East and TDRS_West. Throughout all exercise time will be displayed in seconds. In window Basic Properties choose Units, change measurement of time for seconds and press APPRX. Now companions are added in the scenario. For exa mple, at first in the scenario two transferring geostationary companions (TDRS) are added. In the main window it is necessary to press the companion image. As a result will open Orbit Wizard (the master of a choice of an orbit).


Key Next is pressed. Option Geostationary gets out and is again pressed Next.


It is necessary to be convinced that in a window of the Master of geostationary orbits the longitude (Longitude) matters-100 (a longitude of standing of the companion on equator), then it is necessary to press Next. Further change time of start of viewing of the scenario and the viewing termination on 1 Nov 1997 00:00:00.00 and 2 Nov 1997 00:00:00.00, accordingly. Further it is necessary to change the companion name on TDRS. Now it is necessary to enter one more companion TDRS into the scenario. For this purpose it is necessary to make active a scenario window, to choose in menu Files point Insert. After opening Insert it is necessary to choose the concrete companion from the list of accessible expansions. Further key is pressed to add the companion. Lines of both companions are displayed in the form of lines. That it is better to see companions, it is necessary to click on companions serially and to choose in appeared menu Graphics. The icon of the companion as Marker Style Further gets out.


Addition of companions is carried out by pressing an icon with the co mpanio n image. When there will be a window of the master of a choice of an orbit is pressed Cancel and the companion name on ERS1 changes.

Further parameters of an orbit for ERS1 are entered. Before entering the values resulted in the table, it is necessary to press the button to change value RAAN on Lon Ascn Node (a longitude of the ascending knot).

Orbital Element Start Time Stop Time Step Size Propagator Orbit Epoch Coordinate type Coordinate System Semimajor Axis

Setting 1 Nov 1997 00:00:00.00 1 Nov 1997 04:00:00.00 60.00 J4 Perturbation 1 Nov 1997 00:00:00.00 Classical J2000 3867.7846


Eccentricity Inclination Argument of Perigee Lon Ascn Node True Anomaly

0.0 98.50 0.0 99.38 0.0

After the input termination it is necessary to press the button APPRX.

On ongoing educational scenario should be added to the spacecraft. To do this, again click on the icon with the satellite. When the wizard appears select the orbit should click Cancel and enter the name of the Shuttle. You must open the basic settings for the Shuttle and enter the settings shown in the table, similarly as was done for ERS1.


Before entering the values resulted in the table, it is necessary to press the button to change RAAN on Lon Ascn Node and Semimajor Axis (the main shaft) on Apogee Altitude (apogee height). Orbital Element Start Time Stop Time Step Size Propagator Orbit Epoch Coordinate type Coordinate System Apogee Altitude Perigee Altitude Inclination Argument of Perigee Lon Ascn Node True Anomaly Setting 1 Nov 1997 00:00:00.00 1 Nov 1997 03:00:00.00 60.00 J4 Perturbation 1 Nov 1997 00:00:00.00 Classical J2000 200.0 nm 200.0 nm 28.5 0.0 -151.0 0.0


After finishing, press the OK button. Once you enter the parameters Shuttle, you can change the properties of an object, such as the type and color lines to indicate his line on the Earth's surface, to distinguish the road from other moving objects. To do this, select Shuttle in the main window, click on it, right-click, select Graphics fro m the menu,

on tab Attributes change Line Style (line style) on the Long Dash (long dashed line), Marker Style (marker style) on the Plus and click Apply. Then choose the tab Contours.

Now, should set a place at which the angle can be observed Shuttle. You must make sure that the tab Contours Add Method cursor on Start, Stop, Step. Next, enter a value of 0, 50 and 10 are, respectively, and click Add. In the Level select the first level (0.00) and disable the Label. Then do the same for the other


levels.

Enable

Show

Elevation

Angle

Contours

and

click

OK .

Here's an example view of the map

You can watch satellite orbits in 3-D. In the main window should be allocated and choose Tutorial40 in the Tools menu, click New Window. When you see the map window, click on the last button in the top row - will appear Graphics Properties. Select the tab Projection. Put the values shown in the figure below.

When the scenario is important needed to select the monitoring of the surface (visibility) from satellites. They clearly represent the boundary areas of interest in the Earth's surface. Consider the situation when the ship ran into an iceberg. Create a scope that defines the boundary of the surviving passengers and search the whole of the remaining equipment. Should click on the icon of Area Target at the bottom of the main window, and then call zone - SearchArea, open the Graphics Properties for


SearchArea. Further Attributes tab to change the thickness of the lines (Line Width) at 3, choose None for the Marker Type and disable option Inherit Settings and Show Label. Then click OK. Now you must specify the purpose of observation. You must open a window to set the Basic Properties of the coverage,

enter the longitude and latitude, as shown in the figure. Once the values have been introduced longitude / latitude, press the Insert Point. We have to go to the tab Centriod.


It should disable the Auto Centroid Compute, modify Position Type to Spherical and the latitude 74.9533 and longitude -74.5482, as well as the radius of 3433.1462149. After graduating fro m OK Press. Next, open the window for the Graphics Properties of the iceberg, change the Marker Style to X and click OK.

Suppose we want to find out whether satellite ERS1 see the collapse and whether it can assist in finding and rescuing people. In the main window should be made ERS1, click the right mouse button and select Access from the menu. Then choose from a list of SearchArea objects, press successively Compute, Access ... Reports in the field to see the report of the review of the satellite.

To use the satellite ERS1 for such purposes, it should have on-board scanner and aerial surveillance, to transfer data from the satellite to the Earth. In the main window should be made ERS1, click on the icon with the image sensor and its name is Horizon. In the class of satellites ERS1 will be a subclass of the


sensor. Now you need to set the properties of the object definitions for the sensor on the tab Basic Properties.

Enter the values as shown in the figure, and then click the Pointing.

Should be sent to our satellite sensor strictly on Earth. To do this, you should check that the options Pointing Type was pressed Fixed Elevation and values equal to 90 degrees, and after that, click OK. What follows is to describe the properties of the transmitting antenna mounted on the satellite ERS1, using the steps described above. To set up an antenna, set the Basic Properties for her. It should set the values as shown below.


Then go to the tab Pointing.

We need to ensure the antenna to the specified ground stations. To do this, change Pointing Type in Targeted and Boresight (reference direction) Type for Tracking (Monitoring). Next, select the Baikonur in the list of available objects and click on the arrow to the "right" to add it to the list of existing objects. In the same way, add the remaining objects. Click on OK. To display the new information is necessary to "revive" the scenario. To do this, click on Play. Below the picture shows the result.


Of their choice modeling and visualization of the script can be interrupted. Sensors purposes and objects can be added. For example, if you want to add an object with the na me of Wallops sensor FiveDegElev to open its Basic Properties to set the parameters. Definition tab in the tab, choose Conical and set the Inner Half-angle equal to the value of 0.0 and Outer Half-angle 85.0, leaving the values for the Clock Angles by default. Then select the tab Pointing. On this tab, you should make sure that the options Pointing Type set to Fixed and Elevation value is equal to 90.0. Click OK. Now, open the Graphics Properties window for the sensor and select the tab Projection. On this tab, set the Maximum Altitude at 424.0 nm and Step Count is equal to 1, click OK.


In order for this sensor could be used for another object WhiteSands, should highlight FiveDegElev sensor in the main window, then select Save fro m the menu Files. Now add a sensor to an object WhiteSands, highlighting the main window WhiteSands, and then press the Insert ... menu, Files. Should change the File Type for Sensor and choose FiveDegElev.

3.2. Analiz orbital missions In this section, students will acquire skills in analysis of orbital missions (satellite orbits), master control co mponent script for more information and graphical display. In the process of implementation of the student acquires the skills to create the orbit, display tracks the spacecraft imaging scenarios, changing the way the map display and documentation of results. 1. Changing the parameters of the orbit. If you want to receive information on the height of the perigee and apogee instead of the major axis and eccentricity, it is necessary to click on the icon with an arrow "down" to the right of Semimajor Axis and choose Apogee Altitude in the list that appears.


2. Create a report. Ability to create reports in STK and facilitates data analysis. In STK provides several standard report templates. To create a report in the main window should be made ERS1, right click and select Report from the menu.

If you need to document information about the orientation of the satellite ERS1, for example, through kvaretniony should be choose Attitude Quaternions in the list of templates and click Create to get information.


To close this window, select the menu item Files Close, to print the report in the menu Files should choose Print.

3. Getting information in graphical form. To view the same information in graphical form in the main window should be allocated satellite ERS1 and click Graph on the menu Tools.

Next in the dialog box to choose Solar AER in the style list reports and press Create.


You can click on any point on the graph to obtain numerical information o n its coordinates.

4. Dynamic display of information. You can follow any change in parameters such as azimuth, the longitude o f the ascending node and the distance to the object's dynamics. To do this, select ERS1 in the main window and select Dynamic Display in menu Tools.


In the window that appears, select Solar AER from the list of available templates and click Open , then you should run an animation script.

5. Analysis of satellite communication environment with an object or purpose. To display these processes should be in the main window, select an object and click Santiago Access to the menu Tools.

In the Associated Objects should be selected ERS1 and make sure that the option Show Line, Animate Highlight and Static Highlight included. Next, press Compute.


6. Analysis of the conditions of communication between satellites. An example of analysis and planning capabilities between the two satellites: Shuttle and TDRS_4. To do this, open the Access to Shuttle, select fro m the list TDRS_4 Associated Objects and press Compute. 7. To analyze the ability to support interplanetary missions is possible to analyze the possibility of co mmunication between the satellite and the planet / interplanetary spacecraft. To add a planet or interplanetary spacecraft in the script should click on the icon in the world and na me the new planet, like Jupiter. To do this, open the Basic Properties for the new object.

Definition tab, select the JPL DE-403, then select Jupiter on the menu and click OK. Now add in the script, for example, the telescope Hubble. To do this, choose Insert menu in Files, change the File Type and select the Satellite Hubble.


This is followed by openning window Basic Properties for the sensor and the option to enter Pointing.

Since the sensor telescope must be sent to Jupiter to be changed Pointing Type in Targeted and Boresight Type for Tracking. Next on the list to choose Jupiter Available Targets, click the arrow to the "right" to add it to the Assigned Targets, then click OK. Everything is now ready to establish a link between the telescope and the Hubble Jupiter. It should open the Access to the telescope, Jupiter choose in the list of Associated Objects and click Access. Reports in the field to check the time o f communication.


8. Analysis of the survey the Earth's surface. To display a swath from the satellite as an example of selected Hubble. It should be in the main window, right click and select Swath menu that appears.

Next, you need to change the Ground Elevation at 35.00 ° and enable the option Filled Limits, click Apply.

9. Analysis of move ment in the long interval of time (Long-term Orbit Predictor) To analyze changes in the orbit for example, two years, you should perform long-term prognosis. In the main window, select the icon with the image of the satellite. When you see the master orbit selection, press Cancel. Next, specify the name of the new satellite, for exa mple, LOPSat and open the Basic Properties to specify the data to the satellite.


Enter the numbers shown in the picture. Once values are set, you can click Force Models on the same tab.

In the window that appears, change the Earth Gravity Maximum Degree and Maximum Order at 6. Make sure the option Use Drag off, and the option Use Solar Radiation Pressure on. Then click the OK button and then click OK on the Advanced tab Orbit.